PORTER’S FIVE FORCES AND MARKET STRUCTURE
A financial analyst aiming to establish market conditions and consequent profitability of incumbent firms should start with the questions framed by Exhibit 1: How many sellers are there? Is the product differentiated? and so on. Moreover, in the case of monopolies and quasi monopolies, the analyst should evaluate the legislative and regulatory framework: Can the company set prices freely, or are there governmental controls? Finally, the analyst should consider the threat of competition from potential entrants.
This analysis is often summarized by students of corporate strategy as “Porter’s five forces,” named after Harvard Business School professor Michael E. Porter. His book, Competitive Strategy, presented a systematic analysis of the practice of market strategy. Porter (2008) identified the five forces as:
Threat of entry;
Power of suppliers;
Power of buyers (customers);
Threat of substitutes; and
Rivalry among existing competitors.
It is easy to note the parallels between four of these five forces and the columns in Exhibit 1. The only “orphan” is the power of suppliers, which is not at the core of the theoretical economic analysis of competition, but which has substantial weight in the practical analysis of competition and profitability.
Some stock analysts (e.g., Dorsey 2004) use the term “economic moat” to suggest that there are factors protecting the profitability of a firm that are similar to the moats (ditches full of water) that used to protect some medieval castles. A deep moat means that there is little or no threat of entry by invaders, i.e. competitors. It also means that customers are locked in because of high switching costs.